[FLIP] Unwanted noise affecting simulation

[galagast]

Hi, i have a FLIP simulation set up to only emit from a circle, going outwards. It also collides with a mesh to slide upwards (sort of like a small basin).

Here's the top view of the sim in progress.


Perspective view


Notice that on the lower left quadrant (-X, +Z), i seem to be getting some sort of noise.
My setup does not contain any other velocity source, except for velocity pushing the particles from the center of the circle emitter, going outwards.

The scene is at the origin.
I tried moving the whole scene away from the origin, but i get the same weird noise on the same quadrant.
My hunch is that maybe the FLIP solver has some noise function inside it that needs to have an offset. (I'm in the process of trying to find it inside the solver XD)

Anyone knows or have encountered something similar?

I'm aiming to have all sides to be roughly smooth/circular. Then from there, i'll add in my custom velocities to sculpt the flow.

I'll try and post a simple scene later if i can.. currently i cannot post the actual file XD

[Atom]

I have seen similar reactions in a smoke simulation. There is no way to perfectly expand pyro in a spherical shape.

It might just be the loss to resolution. Try setting your grid scale to 1.0.

Here is an expanding flip particles at Grid 2.0. The circle falls apart after a few frames.

 

Here is Grid 1.0. The circles remains intact longer.

Edited December 21, 2021 by Atom